The Church of England is in disarray after the General Synod narrowly failed to give final approval to legislation introducing the first women bishops.

A draft measure ushering in the prospect of women bishops including a possible future female Archbishop of Canterbury cleared the Houses of bishops and clergy in the General Synod but failed to gain the necessary two-thirds majority among lay members.

If six people had changed their vote from no to yes in the House of Laity the legislation would have received the necessary two-thirds majority.

The vote was billed as the biggest in the 20 years since the General Synod backed the introduction of women priests in 1992 and comes after 42 out of the 44 dioceses of the Church of England backed the legislation.

If the measure had received final approval, it would have gone to the Houses of Parliament before Royal Assent with the first women bishops on course to be appointed as early as 2014.

The result is a blow to the Archbishop of Canterbury, Dr Rowan Williams, and his successor, the Rt Rev Justin Welby, who staked their authority on a yes vote. Speaking afterwards, Dr Williams, who leaves his post at the end of this year after a decade in office, spoke of his "deep personal sadness" at the result.

He said: "Of course I hoped and prayed that this particular business would be at another stage before I left, and of course it is a personal sadness, a deep personal sadness, that that is not the case. I can only wish the Synod and the archbishop all good things and every blessing with resolving this in the shortest possible time."

Around a third of all Church of England clergy are women - they also make up just under a half of all those training for ordination.

Women and the Church (Watch), the campaigning group, said the result was a "devastating blow" to the Church of England. The Rev Rachel Weir, Watch chairman, said: "This is a tragic day for the Church of England after so many years of debate and after all our attempts at compromise. Despite this disappointing setback, Watch will continue to campaign for the full acceptance of women's gifts of leadership in the Church's life."

But the Catholic Group on the General Synod, which backed a no vote, said in a statement: "We regret the Synod was put in the position whereby draft legislation failed at final approval because it was unclear and unfair in its provision for those who, in conscience, are unable to accept the ministry of women as bishops or priests."